Various shoe designs have been developed which include weights for purposes of providing additional exercise or weight training to the wearer of the shoe. U.S. Pat. No. 5,231,776 issued to Wagner incorporates a plurality of small metallic spheres entrapped in a lattice grid matrix molded to the sole. U.S. Pat. Nos. 5,638,613 and 4,709,921 issued to Williams and Valuikas et al., respectively, utilize flattened weights integrated into the soles of shoes, as does U.S. Pat. No. 3,109,245, issued to R. P. Glynn. More advanced shoes have included various means to add varying amounts of weight to the shoe. U.S. Pat. No. 4,777,743 issued to Roehrig, Jr. uses one or more weighted fastening straps disposed about the upper ankle portion of the shoe top. U.S. Pat. No. 4,686,781, issued to Bury includes a chamber in the sole of the shoe designed to accommodate lead shot or similar weighting material. U.S. Pat. Nos. 3,114,982 and 4,458,432, issued to McGowan, and Stempski, respectively, incorporate pockets to hold shoe weights.
Prior art designs for weighted shoes either do not provide a capability to remove or vary the weight attached to the shoe or provide only a limited capacity to vary the weight. Some of the designs include external weight pockets that provide relatively unbalanced weighting and do not integrate smoothly with the appearance of the shoe. Some of the designs allow the shoe weights to shift within cavities in the shoe, increasing the shoe's instability to the wearer.
It is an objective of the present invention to provide for variable weighting of the shoe. It is a further objective to allow the wearer to remove the weight from the shoe entirely without interfering with the structural integrity of the shoe. It is a still further objective of the invention to have the weighting capability integrate smoothly with the appearance of the shoe. It is yet a further objective to permit the wearer to change the weighting of the shoe without the use of external tools.
While some of the objectives of the present invention are disclosed in the prior art, none of the inventions found include all of the requirements identified.